Wang Xiang, Han Xu, Du Ruifeng, Xing Congcong, Qi Xueqiang, Liang Zhifu, Guardia Pablo, Arbiol Jordi, Cabot Andreu, Li Junshan
Catalonia Institute for Energy Research (IREC), Sant Adrià de Besòs, 08930 Barcelona, Spain.
Departament d'Enginyeria Electrònica i Biomèdica, Universitat de Barcelona, Catalonia, 08028 Barcelona, Spain.
ACS Appl Mater Interfaces. 2022 Sep 21;14(37):41924-41933. doi: 10.1021/acsami.2c09272. Epub 2022 Sep 8.
The development of cost-effective bifunctional catalysts for water electrolysis is both a crucial necessity and an exciting scientific challenge. Herein, a simple approach based on a metal-organic framework sacrificial template to preparing cobalt molybdenum nitride supported on nitrogen-doped carbon nanosheets is reported. The porous structure of produced composite enables fast reaction kinetics, enhanced stability, and high corrosion resistance in critical seawater conditions. The cobalt molybdenum nitride-based electrocatalyst is tested toward both oxygen evolution reaction and hydrogen evolution reaction half-reactions using the seawater electrolyte, providing excellent performances that are rationalized using density functional theory. Subsequently, the nitride composite is tested as a bifunctional catalyst for the overall splitting of KOH-treated seawater from the Mediterranean Sea. The assembled system requires overpotentials of just 1.70 V to achieve a current density of 100 mA cm in 1 M KOH seawater and continuously works for over 62 h. This work demonstrates the potential of transition-metal nitrides for seawater splitting and represents a step forward toward the cost-effective implementation of this technology.
开发用于水电解的具有成本效益的双功能催化剂既是一项至关重要的必要任务，也是一项令人兴奋的科学挑战。在此，报道了一种基于金属有机框架牺牲模板制备负载在氮掺杂碳纳米片上的氮化钴钼的简单方法。所制备复合材料的多孔结构在关键的海水条件下能够实现快速的反应动力学、增强的稳定性和高耐腐蚀性。使用海水电解质对基于氮化钴钼的电催化剂进行了析氧反应和析氢反应半反应测试，其表现优异，并利用密度泛函理论进行了合理解释。随后，将该氮化物复合材料作为双功能催化剂用于对经氢氧化钾处理的地中海海水进行全分解测试。组装的系统在1 M氢氧化钾海水中仅需1.70 V的过电位即可实现100 mA cm的电流密度，并能持续工作超过62小时。这项工作证明了过渡金属氮化物在海水分解方面的潜力，并朝着该技术的成本效益实施迈出了一步。
